A British man who lived on death row for 21 years in Ohio is expected to return home on Wednesday a free man, amid serious concerns about his long-term health.

Kenny Richey, 43, from Edinburgh, was released from jail tonight by a court in Ohio after he struck a deal with prosecutors not to contest reduced charges over the death of two-year-old Cynthia Collins in a house fire in 1986.

After fighting for two decades to clear his name - culminating in one stay of execution only an hour before he was to be electrocuted, Richey is expected to fly into Edinburgh airport on Wednesday afternoon with his brother and civil rights campaigners to be welcomed home by his mother Eileen, a launderette manager.

Mrs Richey said she was looking forward to him coming home: "It will probably sink in when he gets off the plane."

Ken Parsigian, Richey's lawyer, said his client was "very excited. It's finally sinking in. There's been a lot of anxiety over the last couple of weeks but this time it feels real. It's just a matter of hours now. "

British human rights campaigners were jubilant over his release. Clive Stafford Smith, legal director of the legal charity Reprieve and a leading campaigner against the US death penalty, said: "After Kenny's heart scare, it is a tremendous relief to see him finally walk free. This is a great day for him and his family."

Stafford Smith, a US-qualified lawyer who first championed Richey's claims that he was wrongly convicted, said his former client's plea bargain did not mean Richey accepted blame for the girl's death.

His deal allowed Ohio's state prosecutors - who have repeatedly refused to accept that Richey was wrongly convicted - to save face and avoid a protracted retrial for the girl's murder.

Although a federal appeal court overturned his conviction last August, leading to judges ordering a retrial, the prosecution had insisted he started the fire which killed Cynthia in a drunken rage following a row with her mother, his former girlfriend.

By pleading "no contest" to much reduced charges of endangering Cynthia's life by failing to honour a promise to babysit her - thus leaving her unprotected when the fire began - as well as an unrelated burglary charge, he had been cleared of the much more serious death row murder conviction.

The precise charges were designed to equal the 21 years he has served, allowing him to walk free.

"There should be no mistake that this deal is nothing short of complete vindication for Kenny," Stafford Smith said yesterday.

"The prosecutors no longer accuse him of murder or having anything to do with starting the fire. Instead, they have charged him with, essentially, failing to babysit.

"For all intents and purposes, he will walk free from jail today completely exonerated - now he must work to get his life back together."

The deal means Richey has no rights to claim compensation from the state of Ohio, leaving him effectively penniless. Although he has signed an exclusive deal with a Sunday newspaper, he has no job in the UK and his supporters believe he faces a difficult and uncertain future.

A former US marine and a self-proclaimed "crazy head" and drunk before his conviction, Richey has had two heart attacks on death row and needs surgery to widen a blocked artery.

Originally due to be released before Christmas, his court hearing was postponed when he was sent to hospital with chest pains hours before he was due in court.

His family and Reprieve are planning to arrange medical checks when he arrives back in the UK, and are working with former death row inmates and miscarriage of justice campaigners to help him adapt to ordinary life.

Parsigian said: "Of course he's not prepared but he's got good things going for him. He has his mother. He's going to try to reconnect with friends. He has been reminiscing about some lake he used to fish in.

"We've had a good talk about how he wants to find a job pretty promptly - those are the kinds of things which bring structure and stability back to your life.

"I think he knows he's going to face a lot of challenges, but that's the price of freedom, right?"